Stack of fan case

ABSTRACT

A stack of fan case in accordance with the present invention includes a first casing and a second casing stacked on the first casing. The first casing has a first surface, a second surface and a locking surface opposite to the second surface. An insertion bore formed on the second surface penetrates the second surface and the locking surface and has an alignment bore, a fastening bore communicating to the alignment bore and a limit bump formed at the fastening bore. The second casing has a third surface, a fourth surface and at least one fastening member protruding on the fourth surface. The fastening member includes a stick-like portion and a limit clasp portion formed at one end of the stick-like portion. The fastening member of the second casing is inserted into the alignment bore of the insertion bore that allows the limit clasp portion of the fastening member to protrude on the locking surface of the first casing, and then the first and second casings are turned to make the stick-like portion of the fastening member pass through the limit bump and be accommodated within the fastening bore, in which the stick-like portion of the fastening member is limited by the limit bump within the fastening bore and the limit clasp portion protrudes on and contacts against the locking surface of the first casing.

FIELD OF THE INVENTION

The present invention is generally relating to a stack of fan case, andmore particularly to a stack of fan case having limit bump.

BACKGROUND OF THE INVENTION

As shown in FIGS. 1, 2, 3 and 4, conventional contrarotation type axialfan has a casing assembly structure including a first casing 110 and asecond casing 120. The first casing 110 has a first surface 111 forminga plurality of first insertion grooves 112 and a plurality of secondinsertion grooves 113 thereon. The second insertion grooves 113 arelocated adjacent to the first insertion grooves 112 and extend to form aprojective moving groove 113 a. Each of the first insertion grooves 112has a clasp-passing bore 112 a and a clasp-moving bore 112 b. The secondcasing 120 has a second surface 121 forming a plurality of clasps 122and a plurality of protrusions 123 thereon. While assembling the firstand second casings 110, 120, the clasps 122 of the second casing 120 arealigned with and inserted into the clasp-passing bores 112 a of thefirst insertion grooves 112 on the first casing 110 and accommodatedwithin the clasp-moving bores 112 b of the first insertion grooves 112,which prevents the first and second casings 110, 120 from separation.Also, the protrusions 123 of the second casing 120 are accommodatedwithin the projective moving grooves 113 a of the second insertiongrooves 113 for preventing the clasps 122 of the second casing 120 fromslipping off the clasp-moving bores 112 b. Accordingly, because it isnecessary to form the second insertion grooves 113 and the projectivemoving grooves 113 a on the first casing 110 and the protrusions 123 onthe second casing 120, and align the protrusions 123 with the secondinsertion grooves 113 and the projective moving grooves 113 a,mold-designing process becomes complicated and difficult.

SUMMARY

The primary object of the present invention is to provide a stack of fancase, which includes a first casing and a second casing. The firstcasing has a first surface, a second surface and a locking surfaceopposite to the second surface. An insertion bore formed on the secondsurface penetrates the second surface and the locking surface and has analignment bore, a fastening bore communicating to the alignment bore anda limit bump formed at the fastening bore. The second casing has a thirdsurface, a fourth surface and at least one fastening member protrudingon the fourth surface. The fastening member including a stick-likeportion and a limit clasp portion formed at one end of the stick-likeportion is inserted into the alignment bore and then locks with thefastening bore. Wherein the stick-like portion of the fastening memberis limited by the limit bump within the fastening bore, the limit claspportion protrudes on and contacts against the locking surface of thefirst casing, which allows the fastening member not to slip off thefastening bore causing a separation of the first and second casings dueto the limit bump that makes the stick-like portion of the fasteningmember be limited by the fastening bore. In addition, the presentinvention not only overcomes the problem of known technique aboutaligning the protrusions with the projective moving grooves of thesecond insertion, but also omits disposition of the known secondinsertion grooves, the projective moving grooves and the protrusions asto cost down.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the first casing of a known fan.

FIG. 2 is a perspective view showing the second casing of a known fan.

FIG. 3 is a top view showing the first casing of a known fan.

FIG. 4 is a top view showing the second casing of a known fan.

FIG. 5 is a perspective view showing the first and second casings of astack of fan case in accordance with an embodiment of the presentinvention.

FIG. 6 is a top view showing the first casing of the stack of fan casein accordance with an embodiment of the present invention.

FIG. 7 is a top view showing the second casing of the stack of fan casein accordance with an embodiment of the present invention.

FIG. 8 is a perspective view showing the fastening member of the stackof fan case is inserted into the alignment bore of the insertion bore inaccordance with an embodiment of the present invention.

FIG. 9 is a cross-sectional view along A-A line of FIG. 8 showing thefastening member of the stack of fan case is inserted into the alignmentbore of the insertion bore in accordance with an embodiment of thepresent invention.

FIG. 10 is a perspective view showing the fastening member of the stackof fan case is inserted into the alignment bore of the insertion boreand the second casing is turned to lock the fastening member with thefastening bore in accordance with an embodiment of the presentinvention.

FIG. 11 is a cross-sectional view along B-B line of FIG. 10 showing thefastening member of the stack of fan case is inserted into the alignmentbore of the insertion bore and the second casing is turned to lock thefastening member with the fastening bore in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

According to an embodiment of the present invention a stack of fan caseis disclosed shown in FIG. 5, 6 and 7 including a first casing 210 and asecond casing 220. As shown in FIGS. 5 and 6, the first casing 210 has afirst surface 211, a second surface 212 and a locking surface 213opposite to the second surface 212. An insertion bore 214 formed on thesecond surface 212 penetrates the second surface 212 and the lockingsurface 213 and has an alignment bore 214 a, a fastening bore 214 bcommunicating to the alignment bore 214 a and a limit bump 214 c formedat the fastening bore 214 b. FIGS. 5 and 7 show the second casing 220having a third surface 221, a fourth surface 222, at last a fasteningmember 223 protruding on the fourth surface 222 and at least one lateral224, wherein the fastening member 223 includes a stick-like portion 223a and a limit clasp portion 223 b formed at one end of the stick-likeportion 223 a. In this embodiment, in order to improve joint strength ofthe first and second casings 210, 220, there are a plurality offastening members 223 and a plurality of insertion bores 214 formed onthe second casing 220 and the second surface 212 of the first casing 210respectively. FIGS. 8 and 10 show joint action of the first and secondcasings 210, 220, FIGS. 9 and 11 are cross-sectional view showing jointaction of the first and second casings 210, 220. The second casing 220is stacked on the first casing 210 shown in FIGS. 8 and 9, the fourthsurface 222 of the second casing 220 faces the second surface 212 of thefirst casing 210, and then the fastening members 223 are inserted intothe alignment bores 214 a of the insertion bores 214, wherein the limitclasp portions 223 b of the fastening members 223 protrude on thelocking surface 213 of the first casing 210 and there is a displacementdifference between the first and second casings 210, 220. Next, thefirst and second casing 210, 220 alone may be turned shown in FIG. 10,11, or the first and second casings 210, 220 are simultaneously turnedthat allows the stick-like portion 223 a of the fastening members 223 topass through the limit bump 214 c and be accommodated within thefastening bore 214 b, wherein the stick-like portion 223 a of thefastening members 223 is limited by the limit bump 214 c within thefastening bore 214 b capable of preventing the fastening members 223from slipping off the fastening bore 214 b causing a separation betweenthe first and second casings 210, 220. The limit clasp portion 223 bprotrudes on the locking surface 213 of the first casing 210 andpreferably contacts against the locking surface 213 as to avoidseparation of the first and second casings 210, 220. In this embodimentreferring back to FIG. 5, each of the fastening bores 214 b has an innerwall 214 d and the limit bumps 214 c are formed and protrude on theinner wall 214 d of the fastening bores 214 b, so that the fasteningmembers 223 may be limited by the limit bumps 214 c within the fasteningbores 214 b. Besides, the limit clasp portions 223 b of the fasteningmembers 223 face the lateral 224 and contact against the locking surface213 of the first casing 210 able to increase axial and radial jointstrength of the first and second casings 210,220. Accordingly, thepresent invention applies the limit bumps 214 c for locking thefastening members 223 to be limited within the fastening bores 214 bthereby omitting disposition and alignment of the known second insertiongrooves and the protrusions, and mold-designing process also can besaved.

In addition, in this embodiment referring again to FIG. 5, 6, 7, thefirst casing 210 further has a first central 215 and at least one firstthrough hole 216, wherein the linear distances L1 between the firstcentral 215 and each of the insertion bores 214 are typically same, thefirst through hole 216 penetrates the first casing 210 and is alignedwith the alignment bore 214 a of the insertion bore 214. The secondcasing 220 further has a second central 225 and at least one secondthrough hole 226, wherein the linear distances L2 between the secondcentral 225 and each of the fastening members 223 are typically same,the second through hole 226 penetrates the second casing 220 and isadjacent to the fastening members 223. The first and second throughholes 216, 226 dispose screws applied by the first and second casings210, 220 for joining with other components (not illustrated).

While the present invention has been particularly illustrated anddescribed in detail with respect to the preferred embodiments thereof,it will be clearly understood by those skilled in the art that variouschanged in form and details may be made without departing from thespirit and scope of the present invention.

1. A stack of fan case comprising a first casing having a first surface,a second surface and a locking surface opposite to the second surface,wherein an insertion bore formed on the second surface penetrates thesecond surface and the locking surface and has an alignment bore, afastening bore communicating to the alignment bore and a limit bumpformed at the fastening bore; and a second casing stacked on the firstcasing and having a third surface, a fourth surface and at least onefastening member protruding on the fourth surface, wherein the fasteningmember includes a stick-like portion and a limit clasp portion and isinserted into the insertion bore, the stick-like portion of thefastening member is limited by the limit bump within the fastening bore,and the limit clasp portion protrudes on the locking surface of thefirst casing.
 2. The stack of fan case in accordance with claim 1,wherein the fastening bore has an inner wall and the limit bump isformed on the inner wall of the fastening bore.
 3. The stack of fan casein accordance with claim 1, wherein the limit clasp portion contactsagainst the locking surface of the first casing.
 4. The stack of fancase in accordance with claim 1, wherein the second casing further hasat least one lateral and the limit clasp portion of the fastening memberfaces the lateral.
 5. The stack of fan case in accordance with claim 1,wherein the first casing further has at least one first through hole,the first through hole penetrates the first casing and is aligned withthe alignment bore of the insertion bore.
 6. The stack of fan case inaccordance with claim 1, wherein the second casing further has at leastone second through hole, the second through hole penetrates the secondcasing and is adjacent to the fastening member.